Light Sensitive Double LED Blinker

Hii friend,

Today I am going to make a circuit of Light Sensitive Double LED Blinker.It means LEDs will blink alternate when no light will fall down on the LDR and LEDs will glow continuously when light will be on the LDR.

Let's get started,

Components required -

(1.) Transistor - BC547 x2

(2.) LDR x2

(3.) LED - 3V x2 {Any color}

(4.) Capacitor - 16V 220uf x2

(5.) Resistor - 220 ohm x1

(6.) Connecting wire.

(7.) Battery - 9V

(8.) Battery clipper

Pin-1 of this transistor is collector,

Pin-2 is Base and

Pin-3 is Emmiter of this transistor.

Solder -ve leg of LED to Collector pin of transistor.

Next solder one leg of LDR to Base pin of the Transistor as solder in the picture.

Next Connect +ve leg of LED to remaining leg of LDR as you can see in the picture.

Next we have to connect one more LED and LDR to another remaining transistor as shown in the picture.

Next solder emmiter pins of both transistors as solder in the picture.

Solder +ve pin of Electrolytic capacitor to Collector pin of 2nd transistor and

Solder -ve pin of capacitor to base pin of 1st transistor as you can see in the picture.

Solder +ve pin of this capacitor to Collector pin of 1st transistor and

-ve pin of capacitor to Base pin of 2nd transistor as solder in the picture.

Solder 220 ohm resistor to +ve leg of LED as solder in the picture.

Now we have to solder battery clipper wire to the circuit.

Solder +ve wire of battery clipper to 220 ohm resistor and

-ve wire to emmiter pin of transistors as you can see in the picture.

Now connect battery to battery clipper and observe that -

1] When light will be on the LDR then Both LEDs will blink continuously as you can see in the picture-1 and picture-2.

2.] When light will not be on the LDR then LEDs will be linking alternately as you can see in the picture-3 and picture-4.

Thank you